Wednesday, February 22, 2012

Superconductor breaks high-temperature record : Nature News : Under normal pressure, iron selenide superconducts up to about 30 K, and Sun's team expected that raising the pressure would disrupt this. The researchers squeezed a single crystal of the material, measuring 100 micrometres in diameter and 50 micrometres thick, between two diamond-tipped anvils. At first, they found exactly what they predicted: superconductivity stopped as the pressure approached 10 gigapascals.

But as they increased the pressure above 11.5 GPa the sample began to superconduct again. “Pressure-induced re-emergence of superconductivity has been not found in any families of high-temperature superconductors.” says Sun. Furthermore, at pressures of about 12.5 GPa, the sample could superconduct at temperatures up to 48 K — setting a new record for iron-selenide superconductors1.